| Full text | |
| Author(s): |
Rosa, P. F. S.
[1, 2]
;
Adriano, C.
[1, 2]
;
Iwamoto, W.
[1]
;
Garitezi, T. M.
[1]
;
Grant, T.
[2]
;
Fisk, Z.
[2]
;
Pagliuso, P. G.
[1, 2]
Total Authors: 7
|
| Affiliation: | [1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil
[2] Univ Calif Irvine, Irvine, CA 92697 - USA
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Physical Review B; v. 86, n. 16 OCT 24 2012. |
| Web of Science Citations: | 15 |
| Abstract | |
Single crystals of Ba1-xEuxFe2As2 were studied by magnetic susceptibility, heat capacity, resistivity, and electron spin resonance (ESR) measurements. Spin-density wave (at T-SDW) and antiferromagnetic (at T-N) phase transitions were mapped as a function of x. For x >= 0.2, we found a single Eu2+ ESR Dysonian line that presents an isotropic linear increase (Korringa) of its linewidth (Delta H) above T-SDW which systematically decreases with decreasing x. In contrast, for a critical concentration x(c) (0.10 < x(c) < 0.20), Delta H decreases with increasing T, suggesting a distinct relaxation process that we associate with a Eu2+ Kondo single impurity regime. The Korringa rate suppression towards the Ba-rich compounds is claimed to be due to the reduction of the q-dependent exchange interaction between the Eu2+ f electrons and the conduction electrons, which is likely associated with an increasing of localization of Fe d electrons. This result may help the understanding of the SDW phase suppression (that can lead to superconductivity) in this class of materials. (AU) | |
| FAPESP's process: | 09/09247-3 - Investigation of pressure induced ordered states in novel complex materials. |
| Grantee: | Cris Adriano |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 10/11949-3 - Electron spin resonance (ESR) in superconducting Fe-based pnictides |
| Grantee: | Priscila Ferrari Silveira Rosa |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 11/01564-0 - Materials sciences on complex and advanced systems |
| Grantee: | Pascoal Jose Giglio Pagliuso |
| Support Opportunities: | Scholarships abroad - Research |
| FAPESP's process: | 11/23650-5 - Investigation of band structure and Fermi surface in advanced complex materials studied by angle-resolved photoemission spectroscopy |
| Grantee: | Cris Adriano |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |
| FAPESP's process: | 06/60440-0 - Study of strongly correlated systems in extreme conditions |
| Grantee: | Carlos Rettori |
| Support Opportunities: | Research Projects - Thematic Grants |